1. Field of the Invention
The present invention relates to an insertion apparatus for inserting an endoscope having an image pickup section into a duct. More particularly, the present invention relates to an endoscope insertion apparatus that includes an inner-side insertion assisting section and an outer-side insertion assisting section, in which each insertion assisting section is equipped with a fixing member that can be fixed to a duct wall.
2. Description of the Related Art
An endoscope has an insertion portion that includes an elongated flexible portion, a bendable bending portion that is connected to a distal end side of the flexible portion, and a distal end portion that is connected to a distal end side of the bending portion. The insertion portion of the endoscope is, for example, anally inserted into a body cavity of a subject to conduct observation and diagnosis of a predetermined region or conduct treatment while observing the predetermined region.
However, when a conventional endoscope is inserted as far as a deep region of a digestive tract, for example, when the endoscope is inserted as far as the small intestine via the large intestine, it is difficult to insert the endoscope to the deep part by merely pushing in the insertion portion because it is hard for the force to be transmitted to the distal end portion due to complicated bends in the intestinal tract. Consequently, when an endoscope is inserted into the large intestine, operations such as angle adjusting, twisting, retracting, and axis retaining are performed, and combined use of air feeding and x-ray fluoroscopy and the like is also performed.
In order to facilitate the insertion operation described above, endoscopes having fixing balloons have been proposed.
For example, Japanese Patent Application Laid-Open Publication No. 2002-65595 discloses a double-balloon endoscope that has two tubes, in which each tube includes a balloon portion that is provided near a distal end of the tube and which can be inflated and deflated by means of fluid, a fluid channel that communicates with the balloon portion, and a fluid feeding apparatus which is provided at a proximal end portion of the tube and communicates with the fluid channel.
Further, Japanese Patent Application Laid-Open Publication No. 2002-301019 discloses a sliding-tube type endoscope that includes an endoscope body that is provided with a balloon for fixation of the endoscope body at an outer circumferential portion of the distal end thereof, and an overtube that is provided with a balloon for fixation of the tube at an outer circumferential portion of the distal end thereof and into which the endoscope body is inserted.
FIG. 1 is a view that illustrates procedures for inserting a double-balloon endoscope into an intestinal tract 9A. According to the double-balloon endoscope, an overtube 240a can be fixed to an intestinal wall 9 of the intestinal tract 9A by a balloon 230a that is attached to the distal end thereof, and an endoscope 202a can be fixed to the intestinal wall 9 by a balloon 230b that is attached to the distal end thereof. Therefore, by repeating an operation whereby the endoscope 202a advances to the deep part side and the overtube 240a thereafter progresses by the amount that the endoscope 202a has advanced while the balloon 230a and the balloon 230b are alternately fixed to the intestinal wall 9 in accordance with the procedures illustrated in FIG. 1(A) to (H), the endoscope 202a arrives at a deep part of the large intestine or the small intestine.
FIG. 2 is a view for describing a method of inserting a double-balloon endoscope. FIG. 3 and FIG. 4 are views for describing a method of inserting a sliding-tube type endoscope.
Regions such as the sigmoid colon and transverse colon of the large intestine are free regions at which the intestinal tract 9A is not fixed to the abdominal cavity and at which the intestinal tract 9A can freely move inside the abdominal cavity. Therefore, in some cases the double-balloon endoscope cannot be inserted well at a free region. As shown in FIG. 2A, when a double-balloon endoscope is used, first, a balloon 230b attached to an endoscope 202a is inserted to a deep side. Next, as shown in FIG. 2B, the balloon 230b is inflated so that the balloon 230b is fixed to the intestinal wall 9. Subsequently, as shown in FIG. 2C, it is attempted to glide a balloon 230a that is attached to an overtube 240a along the inside of the intestine to approach the balloon 230b at the deep part side. However, in this case, if there is a large amount of friction between the intestinal wall 9 and the balloon 230a, the intestinal tract 9A shortens into a bellows-like shape. As a result, although the distance between the balloon 230a and the balloon 230b is shortened, the overtube 240a is not moved relative to the intestinal wall 9.
Next, as shown in FIG. 2D, the balloon 230a is inflated and fixed to the intestinal wall 9, and the balloon 230b is deflated. The surgeon then attempts to advance the balloon 230b towards a deep region by extending the endoscope 202a. However, even in the deflated state, the balloon 230b slips inside the intestine and does not move due to friction between the balloon 230b and the intestinal wall 9. Consequently, the intestinal tract 9A that has been shortened into a bellows-like shape is stretched back into its original state. More specifically, since the intestinal tract 9A returns from the state in FIG. 2D to the state in FIG. 2A, the endoscope 202a cannot move in the direction of the deep region of the intestinal tract 9A.
On the other hand, in the case of a sliding-tube type endoscope also, there are cases in which the sliding-tube type endoscope cannot be inserted well at a free region. As shown in FIG. 3A, according to a sliding tube method, the surgeon initially inserts an endoscope 302a as far as a region to which the endoscope 302a can be inserted without difficulty. Next, as shown in FIG. 3B, the surgeon inflates a balloon 330b to fix the balloon 330b to the intestinal wall 9, and pushes in an overtube 340a that has a balloon 330a to feed the overtube 340a to the deep region side. However, if the balloon 330a does not move while sliding with respect to the intestinal wall 9, even if the surgeon pushes in the overtube 340a in the direction of the deep region, the only result is that the intestinal tract 9A is shortened into a bellows-like shape between the balloon 330a and the balloon 330b. Consequently, as shown in FIG. 3C, when the balloon 330b is deflated, the intestinal tract 9A that had been shortened expands. More specifically, since the intestinal tract 9A returns to the state in FIG. 3A from the state in FIG. 3C, the surgeon cannot move the endoscope 302a in the direction of the deep region of the intestinal tract 9A.
Further, according to the sliding-tube type endoscope, the endoscope insertion portion is used in combination with the overtube 340a. Therefore, as shown in FIG. 4, an operation by which a surgeon pushes the endoscope into a deep region of the intestinal tract 9A using a hand 115 or the like is performed via the overtube 340a that covers the endoscope 302a. 